Speculum barrel and retainer ring assembly

ABSTRACT

An open ended retainer ring or spring ring is combined with a repetitively manually operable linkage system at the opposed ends of the ring to expand and contract the ring. The ring is used in the handle part of a medical sigmoidoscope or speculum instrument to expand over the end of a plastic tube and contract within a groove in the tube to retain and release the tube with respect to the handle of the instrument.

United .States Patent [191 Fiore [4s] Junel l, 1974 [73] Assignee:

[ SPECULUM BARREL AND RETAINER RING ASSEMBLY [75] lnventorf John M. Fiore, Troy, NY.

Bio-Analytical Laboratories, Inc.,

Troy, NY.

[22] Filed: Nov. 7, 1972 [21] Appl. No.: 304,570

[52] U.S. Cl. 128/6 [51] Int. Cl A61b H06 [58] Field of Search 128/3, 4, 5, 6, 7, 8, 9,

{56] References Cited UNITED STATES PATENTS 2,544,914 3/1951 Cameron 128/6 3,071,129 1/1963 Wasserman 128/6 7/1972 Fiore 128/6 FOREIGN PATENTS OR APPLICATIONS 1,234,920 6/1964 Germany 128/6 Primary Examiner-Lucie I-l. Laudenslager Attorney, Agent, or Firm-James J. Lichiello 57 ABSTRACT An open ended retainer ring or spring'ring is combined witha repetitively manually operable linkage systemat the opposed ends of the ring to expand and contract the ring. The ring is used in the handle part of a medical sigmoiclo'scope or speculum instrument to expand over the end of a plastic tube and contract within a groove in the tube to retain and release the tube withrespect to the handle of the instrument.

15 Claims, 3 Drawing Figures SPECULUM'BARREL AND RETAINER'RING ASSEMBLY This invention relates to a retainer ring assembly for a speculum instrument barrel and more particularly .to a manually operable latch type retainer ring assembly in a handle unit of a medical speculum to releaseably secure a specially adapted speculum barrel or tube therein. I

BACKGROUND OF THE INVENTION In US. Pat. No. 3,675,641 Fiore, assigned to the same assignee as the present invention, there is disclosed a medical speculum instrument, for example, a sigmoidoscope. This instrument comprises a handle unit and a speculum barrel or tube which is releaseably failure or jamming. The latch means also must provide a very secure peripheral attachment and an effective seal for the tube against the handle assembly, but be immediately releaseable in a predetermined trajectory or direction.

' OBJECTS OF THE INVENTION Accordingly,.it is an object of this invention to provide an improved speculum barrel and latch assembly.

It is another object of this invention to provide a spring ring or snap ring latch assembly to releaseably secure a barrel in a speculum instrument.

It is another object of this invention to provide a mechanical linkage and spring ring assembly to releaseably secure a barrel to a speculum instrument.

It is a further object of this invention to provide a cam operated spring ring assembly which circumferentially engages a groove in a barrel member extension to retain the barrel member in a speculum instrument.

It is yet another object of this invention to provide a camming mechanism cooperative .with the opposed open ends of a spring ring to retain a speculum barrel in a sigmoidoscope. BRIEF DESCRIPTION OF THE INVENTION The above objects are attained in a preferred form of this invention by having a circumferentially enlargeable open ended spring or snap ring retained in an annular groove in a speculum instrument handle. A speculum BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of this invention will be better understood when taken in connecof FIG. 1.

FIG.. 2, is an illustration. of thespring ring of FIG. 1.

.FIG. 3 is an illustration of the DESCRIPTlON OF PREFERRED EMBODIMENTS Referring now to FIG.'1, there is disclosed, in part, a speculum instrument assembly 10 which comprises a barrel member ll and-a handle unit 12. Both elements 11 and 12 are-more fully described and claimed in'U.S. Pat. No. 3,675,641 Fiore, which is incorporated by reference herein.

Briefly described, the barrel member 11 is preferably an elongated tapering hollow tube of a single use disthe outer wall or surface of barrel extension 15. Groove 16 is defined on one side by a tapering section17 of the barrel extensionlS and on the other side by a straight walled section 18. One side wall 19 of groove 16 is a squared off or butt wall and the other side wall 20 tapers slightly to the top of the groove, is rounded off and joins smoothly with the taper section 17. The tapered section v17 is best defined as being'essentially frusto conical in shape. It may be desirable in some instances that the heightof the wall 20 be slightly less than that of butt wall 19.

The handle unit 12 .of the speculum instrument, as described inthe above noted patent, has a head part 21 which encircles the barrel extension 15, and a transverse part 22 which extends in a transverse direction to the longitudinal axis of barrel 11. It suffices for this invention that the handle unit comprises a suitable aperture so that the medical practitioner can peer through the barrel ll axially from the proximal to the distal end. The head 2l of the handle unit 12 encircles the barrel extension 15 by means of an appropriate circumferential wall 23 therein. In one form of this invention the wall 23 combines with other structure of the handle unit to define an annular recess 24. Within the surrounding wall 23 is a groove 25 whichis positioned in opposite and complementary relationship to groove 16 in the barrel extension 15. Groove 25, however, may have similar side wallson both sides thereof.

Within groove 25 there is positioned a loose fitting ring member 26. Ring member 26 projects into recess 24 or alternately stated the inside diameter of ring 26 is less than the inside diameter of circumferential wall 23. Ring'member 2,6 is of the kind known in the art as a spring ring or snap ring. A preferred ring 26 is illustrated'in FIG. 2. In FIG. 2 ring 26 is shown in a frontal elevational view. Ring 26 is an open ended ring defining opposed separate end lobes 27 and 28 which are in close spaced and abutting relationship. As illustrated in camming mechanism FIG. 1, the ring 26'is of rectangular cross section but its lateral configuration is of a changing width, being minimal adjacent the end lobes, and taperingly increasing to a maximum at the halfway point circumferentially. These rings have been known as Kohinoor rings. Because of the described shape of these rings, lateral separation of the ends will result in a total increase of the circumference of the defined circle. Stated another way, the lateral separation of the ends will increase the radius of the described circle unidirectionally. Such a ring shape, therefore, greatly facilitates expansion of the ring to fit over circular shafts and rods when the rings are used as'locking devices.

Ithas been discovered in this invention that these rings may be combined with a mechanism for expanding the open end and the combination then can be used as a releaseably securing or latch mechanism. For example, the lobes or enlarged ends 27 and 28 are adapta-V shaped cam head 33 with a nose extension 34.

In FIG. I, when the button is depressed the cam head 33 is forced between the lobe ends 27 and 28 of ring 26 separating the ends and increasing the circumference of ring 26. When the button 30 is released the spring action of the ends 27 and 28 of ring 26 on the cam head 33 forces the cam head 33 into its original position as illustrated in FIG. 1.

The barrel member 11 may be inserted into the handle unit 12 with or without depressing the button'30. During insertion of the barrel, the tapered section 17 enters ring 26 forcibly expanding it as the taper 17 becomes larger and forcing the ring to expand increasingly until the 'ring snaps into the barrel extension groove 16. Button 30 may also be depressed during this insertion to facilitate ring expansion, and although de-' sirable, it is not necessary to do so.

An air seal is provided'for the barrel extension 15 when it is inthe recess 24 .by means of a suitable resilient gasket adjacent the bottom or end wall of recess 24. The barrel extension 15 is of a predetermined length so that a positive seal is made with the end of the barrel extension at the time when ring 26 snaps into groove 16. Also the end wall 20 of groove 16 is so formed and tapered that ring 26 exerts an axial force on the barrel extension 15 forcing the tapered end 17 against the sealing gasket 35.

In order to release the barrel 11, the speculum device is usually held ina downward direction so that gravity tends to withdraw the barrel 11 from the handle 12. Then button 30 is depressed to enlargering 26 and move it out of groove 16, and the barrel 11 drops free. More importantly as ring 26 becomes larger and moves out of groove 16 the nose section 34 of cam 29 engages the hand guard 14 of barrel l1 and starts to push it out of the handle 12 in a predetermined tilt and direction to provide a positive release. Even without a hand guard section the nose section 34 may be adapted to push against any appropriate surface of the barrel 11 to provide the positive ejection desired. When ring 26 4 rides out of groove 16 and barrel ll commences to move out of'the handle 12 a release of the button 30 permits ring 26 to contract about the tapered section 17 thus providing an additional axial impetus to the barrel 11 to move it from handle 12. In ordinary operation with complemtary action between the nose section 34, the tapered section 17 and ring 26 and the resilient seal 35, a momentary depress and release motion of button 30 provides a positive ejection of the barrel member 11 in a predetermined direction (with respect to the handle unit) when the instrument is held in various positions. When barrel member 11 is engaged by ring 26 the lock up is very firm and non-yielding. The handle member 12 may be manipulated so that a speculum barrel 11 is fully inserted within a body opening moved about axially or rotatably and sometimes angularly without relative movement of the barrel 11 in the handle 12-or any breakage of the air seal. The preferred ring 26 inherently has a very large constricting force grasping the barrel extension 15 of barrel 11. This is due to the rectangular cross-section as well as to the varyingthickness of the ring in plan view. A specific example of such a ring which is quite similar to the FIG. 2 ring is a Truarc retaining ring, series 5,100 of Waldes Kohinoor, Inc. Other rings of constant cross-section may be employed with some modification of cooperating parts to provide the above described features. In addition various other linkage systems can be adapted to expand ring 26 although the cam arrangement as described is believed to be one of the more advantageous. I

The camming action may be facilitated by beveling the edges of end lobes 27 and 28 which bear against the cam head 33. Ordinarily, the spring ring26 as obtained commercially is provided with a pair of apertures 36 and 37 drilled through end lobes 27 and 28, and the lobes are fairly close together. To modify the ring and facilitate the cam operation, the holes are slotted as illustrated in FIG. 2 so that a wider and larger cam head may be employed and so that the combined end lobes 27 and 28 provide a transverse retaining groove or slot 39 in which the cam head slides and is retained.

This invention thus provides a releaseably securing means for mechanically and temporarily securing and releasing a disposable barrel member to a speculum handle unit. The mechanical means is repetitive and manually operable such as cabinet latches are repetitively operable, as opposed to fixed attachment means such as screw thread means. The .ring means for. the latch assembly provides maximum gripping force and ease of expansion and contraction. These features are most pronounced in the spring ring construction and design of FIG. 2. The ring, however, does not require a groove 16 in the barrel extension 15. A single wall 20 which may be described as a-shoulder performs in an identical manner. Any raised rib or ridge over which the ring canexpand and contract will serve the purpose of a positive and fixed retention means. However, the retention means of whatever kind must be adaptable for engagement by a ring clamp means, i.e. circumferential engagement by ring 26.

The actual circumferential engagement of the ring 26 about barrel extension 15 is caused by a release of tension in ring 26, i.e., ring 26 engages barrel extension 15,

when ring 26 is in its relaxed state. Obviously the spring ring clamping force can be obtained by suitable linkage which closes ring 26 about the barrel, for example by a toggle action and a release of the toggle expands ring 26 to retain the barrel.

While other modifications of this invention and variations of apparatus may be employed within the scope of this invention and have not been described or illustrated, the invention is intended to include all such modifications as may ordinarily be embraced within the following claims.

What I claim as new is:

1. ln a speculum instrument having a handle unit and a releaseably secured speculum barrel, the improvement comprising a. a hollow cylindrical extension on said barrel adapted for insertion in a recess in said handle unit,

b. an open ended spring ring positioned concentrically in said recess in surrounding relationship to said extension to grip said extension to retain said extension in said handle unit,

0. said spring ring having its open ends in spaced abutting relationship,

d. and ring engaging means in said handle and engaging said open ends of said ring to expand and contract said ring about said extension to releaseably secure said speculum barrel in said handle unit.-

2. in a speculum instrument having a handle'unit and a releaseably secured speculumbarrel, the improvement comprising a. a hollow cylindrical extension on said barrel adapted for insertion in a recess in said handle unit,

b. an open ended spring ring positioned concentrically in said recess in surrounding relationship to said extension,

c. said spring ring having its open ends in close spaced abutting relationship,

d. the inside diameter of said ring being less than the outside diameter of said extension,

e. expanding means in said handle unit and engaging the open ends of said ring to expand said ring so that it slides over said extension to releaseably secure said extension in said handle unit.

3. The invention as recited in claim 1 wherein said extension has circumferential ring clamp means thereon to receive said spring ring and lock said barrel to said handle unit.

4. The invention as recited in claim 1 wherein said extension has'a circumferential groove therein to receive said spring ring and lock said barrel to said handle unit.

'6 5. The invention as recited in claim 2 wherein said expanding means comprises a cam head adapted to be Mar iFerted be tween and withdrawn from said ring ends to expand end contract said ring.

6. The invention as recited in claim 3 wherein said cam head is adaptedto expand said ring and simultaneously push against said barrel to 'move said barrel. out of said handle unit. I

7. The invention as recited in claim 4 wherein the ends of said ring are enlarged to define lobe-like appendages extending radially from the. ring circumference.

8. The invention as recited in claim 6 wherein said barrel includes a radial extension extending adjacent said ring lobes.

9. The invention as recited in claim 8 wherein said cam head is adapted to expand said ring and simultaneously push against said radial extension to move said barrel out of said handle unit.

10. In a speculum instrument having a handle unit and a detachable barrel, releaseably securing latch means for said barrel comprising a. a circumferential wall means defining a recess in said handle,

b. said wall having a coaxial circumferential groove therein, i

c. an open ended spring ring in said groove and projecting circumfcrentially into said recess,

d. manually openable means in said handle unit acting on the ends of said ring to expand said ring to grasp a barrel inserted therein.

11. The invention as recited in claim 10 whereinsaid ring has its ends in closely spaced abutting relationship.

12. The invention as recited in claim 11 wherein said manually operable means comprises a wedge shaped cam head adapted to be forced between said ring ends to expand said ring.

13. The invention as recited in claim 12 wherein said cam head includes an axially projecting nose section adapted to push against said barrel.

14. The invention as recited in claim 13 wherein said ring has a rectangular cross section and whose height increases incrementally over one half of its circumfersaid cam head in sliding relationship. 

1. In a speculum instrument having a handle unit and a releaseably secured speculum barrel, the improvement comprising a. a hollow cylindrical extension on said barrel adapted for insertion in a recess in said handle unit, b. an open ended spring ring positioned concentrically in said recess in surrounding relationship to said extension to grip said extension to retain said extension in said handle unit, c. said spring ring having its open ends in spaced abutting relationship, d. and ring engaging means in said handle and engaging said open ends of said ring to expand and contract said ring about said extension to releaseably secure said speculum barrel in said handle unit.
 2. In a speculum instrument having a handle unit and a releaseably secured speculum barrel, the improvement comprising a. a hollow cylindrical extension on said barrel adapted for insertion in a recess in said handle unit, b. an open ended spring ring positioned concentrically in said recess in surrounding relationship to said extension, c. said spring ring having its open ends in close spaced abutting relationship, d. the inside diameter of said ring being less than the outside diameter of said extension, e. expanding means in said handle unit and engaging the open ends of said ring to expand said ring so that it slides over said extension to releaseably secure said extension in said handle unit.
 3. The invention as recited in claim 1 wherein said extension has circumferential ring clamp means thereon to receive said spring ring and lock said barrel to said handle unit.
 4. The invention as recited in claim 1 wherein said extension has a circumferential groove therein to receive said spring ring and lock said barrel to said handle unit.
 5. The invention as recited in claim 2 wherein said expanding means comprises a cam head adapted to be axially inserted between and withdrawn from said ring ends to expand end contract said ring.
 6. The invention as recited in claim 3 wherein said cam head is adapted to expand said ring and simultaneously push against said barrel to move said barrel. out of said handle unit.
 7. The invention as recited in claim 4 wherein the ends of said ring are enlarged to define lobe-like appendages extending radially from the ring circumference.
 8. The invention as recited in claim 6 wherein said barrel includes a radial extension extending adjacent said ring lobes.
 9. The invention as recited in claim 8 wherein said cam head is adapted to expand said ring and simultaneously push against said radial extension to move said barrel out of said handle unit.
 10. In a speculum instrument having a handle unit and a detachable barrel, releaseably securing latch means for said barrel comprising a. a circumferential wall means defining a recess in said handle, b. said wall having a coaxial circumferential groove therein, c. an open ended spring ring in said groove and projecting circumferentially into said recess, d. manually openable means in said handle unit acting on the ends of said ring to expand said ring to grasp a barrel inserted therein.
 11. The invention as recited in claim 10 wherein said ring has its ends in closely spaced abutting relationship.
 12. The invention as recited in claim 11 wherein said manually operable means comprises a wedge shaped cam head adapted to be forced between said ring ends to expand said ring.
 13. The invention as recited in claim 12 wherein said cam head includes an axially projecting nose section adapted to push against said barrel.
 14. The invention as recited in claim 13 wherein said ring has a rectangular cross section and whose height increases incrementally over one half of its circumference.
 15. The invention as recited in claim 14 wherein said ring ends are in the form of lobes having a defined transverse slot therein adapted to receive and retain said cam head in sliding relationship. 